Caulking guns or adhesive dispensing tools are well known in the art and are used often by construction workers for dispensing disposable tubes of adhesive materials such as caulk, sealant, tar and the like. There are known hand powered or manually powered caulking guns for extruding material from adhesive tubes. However, due to the frequent nature at which construction workers use caulk and/or other adhesive materials, manually powering a caulking gun is a rather arduous task. This is particularly true in colder weather when caulk and other adhesive materials become more viscous and therefore more difficult to extrude. Frequent manual operation of a hand powered caulking gun can cause hand and muscle discomfort to the user, which in turn can result in less efficient work.
There are known attempts at providing motorized caulking guns that can eliminate much of the manual labor needed to manually power the caulk gun. As far as cost and practicability are concerned, it is desirable that the motorized caulking gun be powered by commonly used detachable power tool, such as an electric drill for example. In most prior attempts, the motorized caulking guns have a drive mechanism which is powered by a rotary power tool. The drive mechanism often carries a drive plate to drive the plunger in a disposable tube of caulk.
However, a particular problem associated with prior art motorized caulking guns is that they are not easy to use on roof and floor type surfaces. Motorized caulk guns typically have a very short length or require a form of manual manipulation which requires the user to bend over or squat to apply adhesive material to floor or roof surfaces. This often causes discomfort to the backs and legs of construction workers who apply material to floor or roof surfaces. Such discomfort can often slow down the speed at which workers work and lead to work related injuries. The short length of these caulking guns also makes it hard to reach distant caulking surfaces, such as for sealing elevated sides of glass or plastic windows.
Another problem associated with some prior motorized caulking guns is that it is difficult to manipulate the caulk gun for fast application of adhesive material. For example in U.S. Pat. No. 5,027,984 to Gakhar, there is disclosed a caulking gun which is driven by an electric screwdriver. However, operation of the motorized caulking gun in Gakhar would appear to require both hands to be continuously and firmly holding the tool with one hand on the power tool and the other hand on the caulk receptacle to direct and prevent rotation of the caulk tube. This manipulation would also appear to cause workers to excessively bend and squat when dispensing material along floor or roof surfaces.
There are also known attempts at providing motorized adhesive dispensing tools which use detachable drills as exemplified by U.S. Pat. Nos. 3,997,084 to Davis Jr., 4,260,076 to Bergman and 4,322,022 to Bergman. These above mentioned patented devices align the drill in a plane parallel to the caulk receptacle which provides an overall shorter length caulking gun, which as was mentioned causes difficulties when applying material to floor and roof type surfaces. By mounting the drill in a plane offset from the receptacle, the drive mechanisms of these patented devices also require complex gears and the like to drive the pusher plate through the receptacle. The use of multiple gears and the like creates undue complexity and cost.